Last week I bought an iPad 2. I was testing the file managers iStorage and Goodreader. Both apps can connect to an SFTP server, so I tried my N810 and voila ! it works (I have sshd installed on the N810).
So I can transfer files from the iPad to the N810 easily.
I think it also works on the N800 or N900 and , on the other side with an iPhone.